Touch voltage is not enough - meeting our duty of care

摘要

Indirect shock safety targets are considered by many to be dependent upon only a few variables. However, not only are the safety targets dependent upon more factors, but in practice it is difficult for a designer to characterise and guarantee earthing system performance to a strict tolerance. The companion paper [1] addressed how modeling applicability and validity may be met, as well as identifying critical parameters to which performance outcomes are sensitive. This paper examines how to minimise or accommodate uncertainty for those parameters identified as critical. It also identifies a range of contingencies that require assessment, and possible remedial measures incorporated in the design in order to ensure the earthing system meets the duty of care at commissioning and into the future.